conscious choice to change from the default to All.
First, the default listing is set by the instance administrator so we can’t be sure of what is the default in the first place.
Second, one of the most common criticisms carried against open source developers is the tendency to provide too many configuration choices to end-users instead of streamlining the interface, which leads to creation of footguns.
Making it so easy to browse by all is one such footgun.
These “lemmy community syncing” tools is also a footgun. The people running those scripts are basically forcing all content from all communities to be copied across the instances. (curiously, if people were not running these scripts, the likelihood of them getting “hit” by alien.top would be quite small).